1. Field of the Invention
This invention relates generally to liquid metering devices.
2. Description of the Prior Art
Liquid metering devices serve a number of purposes in industry, agriculture and the home. For example, in U.S. Pat. No. 3,487,847 R. A. Scott describes a liquid level control device for providing water for small farm animals. Scott's device utilized a motorized compressor and feedback controls for forcing water from a main reservoir into a number of individual drinking bowls.
A number of other patents illustrate other uses for liquid metering devices. In U.S. Pat. No. 878,750 a liquid metering device is used as a liquid soap dispenser, in U.S. Pat. No. 3,486,525 a metering device is used in an ice cream making machine, and in U.S. Pat. No. 2,699,886 a device automatically meters a small amount of liquid deodorant onto soiled diapers. In U.S. Pat. No. 2,374,076 A. Burckhardt et al teaches a liquid level control means for providing liquids at two different levels which could be used as part of a liquid metering device.
All of the liquid metering devices found in the prior art either require electrical or mechanical energy input for their operation. For example, the device of U.S. Pat. No. 878,750 requires that a user push a button to receive a metered portion of soap. In U.S. Pat. No. 2,699,886 the device requires that a person open and close the diaper hamper lid to dispense a quantity of deodorant. And, of course, Scott's device requires electricity to run its compressor.
A problem that the prior art has not apparently addressed is how to provide a liquid metering device that does not require electrical or mechanical power for its operation. Such a device would be useful in locations where automatic operation is required and where providing electrical power is difficult or expensive.